Abstract
Understanding trends in selectivity is of paramount importance for multi-electron electrochemical reactions. The goal of this work is to address the issue of 2e– versus 4e– reduction of oxygen on metal surfaces. Using a detailed thermodynamic analysis based on density functional theory calculations, we show that to a first approximation an activity descriptor, ΔGOH*, the free energy of adsorbed OH*, can be used to describe trends for the 2e– and 4e– reduction of oxygen. While the weak binding of OOH* on Au(111) makes it an unsuitable catalyst for the 4e– reduction, this weak binding is optimal for the 2e– reduction to H2O2. We find quite a remarkable agreement between the predictions of the model and experimental results spanning nearly 30 years.
Original language | English |
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Journal | The Journal of Physical Chemistry Letters |
Volume | 3 |
Issue number | 20 |
Pages (from-to) | 2948-2951 |
ISSN | 1948-7185 |
DOIs | |
Publication status | Published - 2012 |
Bibliographical note
© 2012 American Chemical Society. ACS AuthorChoice - This is an open access article published under an ACS AuthorChoice License, which permits copying and redistribution of the article or any adaptations for non-commercial purposes.Keywords
- selectivity
- activity volcano
- electrocatalysis
- fuel cells
- hydrogen peroxide
- lithium-air batteries